Resolve "Integrate model-driven optimisation"

Integrated model-driven optimisation. It works with tree-like models and is based on the DL model. For future improvements, we should work directly on ecore models.

The MDO-part can be used by configuring a model-genotype. There are a bunch of MDO-specific mutators:

• feature-swap-crossover
• literal-mutator
• array-size-mutator
• array-reorder-mutator

Closes #73 (closed)

added feature confirmed discussion labels

assigned to @berber

merged